Film turning station

ABSTRACT

A turning station ( 1 ) for changing the mutual orientation of the function layers of film sheets ( 2, 3 ) is shown, which ( 2, 3 ) are transported along their longitudinal directions (z) and which ( 2   a, b ) extend in a direction (x) along their direction of transport (z) and in a direction orthogonal to it, whereby the function layers of the film sheets ( 2, 3 ) follow successively in sequence in the third spatial direction (y).  
     In contrast to the prior art, the devices ( 5, 6, 7, 8 ) for guiding the first film sheet ( 2 ) are provided, which ( 5, 6, 7, 8 ) guide the first film sheet ( 2 ) to the other side of the plane, which is formed by the directions of extension (x) and (z) of a second film sheet ( 3 ).

The invention relates to a turning station for changing the mutual orientation of the function layers of film sheets according to the preamble of the patent claim 1.

Such type of turning stations can be used in equipment for production of multilayer film sheets, which frequently have an external function layer. Such an equipment has been described, for instance, in DE 296 21 374 U1. In it, a blow film extruder is shown, with which a two-layer or multilayer film tube can be produced, which exhibits an adhesive function layer on its inner side. From this film tube, film sheets can be prepared, for example, by slitting in this case. After the reversal, these film sheets can be winded up on independent rolls.

However, with the above described equipment, it is possible only to wind the film sheets so that the function layer lies on the outside. One may, however, also want to wind one of the film sheets in such a manner that the function layer lies in the inner side. However, a function layer in the sense of this invention need not be limited only to an adhesive layer, it can also be any arbitrary layer with special properties, for example, in connection with its color or transparency.

To improve the extrusion device, which extrudes film sheets which have adhesive layers on their outer side, DE 195 01 668 C1 proposes to cut this film into film sheets, to turn one of the two sheets by means of a turning device developed specially for that purpose, and thereafter to reverse it. In this manner it can be ensured that the turned film sheet is not guided through the air turning bars of the unloading device along its adhesive layer.

The underlying problem of the present invention lies in proposing a turning station with a different construction.

This problem is solved by the characterizing features of the patent claim 1, according to which the proposed turning station comprises devices for guiding a first tube sheet, which guide the first film sheet on the other side of the plane, which is formed by the directions of the extension of a second film.

To understand the other advantageous possibilities of the embodiment of a device according to the invention, one must note that the winding direction of a film with function layers on a film roll often plays a major role in the further processing. This is the case, for instance, with the die head extruders, in which the adhesive, colored or other films are extruded, whereby the film tube is subsequently separated into two film sheets and winded at two winding positions.

In the prior art, in such a device, the winding direction of both the winding positions is changed in order to maintain the film roll with the desired arrangement of function layers.

Winding positions, in which a reversal of the direction of the rotation is necessary, are, however, costly, and are not present in most of the older equipment.

With the device according to the invention, in which the position of the function layers of the film tubes, which are supplied, and in which a film tube is formed beforehand, it changes in such a manner that the function layers, which lie on the inner side in the film tube, lie outside and vice versa, can be reversed in the direction of the winding at both the winding positions without reversal of the direction of rotation.

This is possible, for instance, in that, also on the other side of the plane, which is formed by the directions of extension of the second film, devices are provided for reversing the first film.

This is a very simple enhancement of the construction according to the invention. If one wants to provide for turning the films, as in DE 195 01 668 C1, which leads to it that the function layers, which lie on the inside, lie on the outside and vice versa, then one needs such a device for each film sheet.

Other advantageous embodiments according to the invention follow from the description of the objects, the drawings and the claims.

The individual figures show:

FIG. 1 Perspective view of a turning station according to the invention

FIG. 2 Side view of a turning station according to the invention

The FIGS. 1 and 2 show a turning station according to the invention, into which two film sheets 2, 3 are fed through different guide rollers 4, whereby the film sheets are produced, for example, by means of a film extruding and film unloading device shown in DE 296 21 374 U1. The film sheet 3 is guided through the turning station in a straight direction along its direction of transport z. The film tube 2, which is guided at first above the film sheet 3, is guided within the turning station 1 through a turning bar 5. The turning bar 5 is thereby advantageously arranged parallel to the plane, which is fixed by the direction of transport z and the direction of extension y of the film sheet 3 within the turning station 1. The turning bar 5 makes an angle of 45 degrees with the direction of transport z. However, the turning bar 5 can also be oriented in any arbitrary direction. The film sheet 2 is guided thereafter by means of a deflection roller 6, whose direction of rotation runs advantageously parallel to the direction of transport z. The film sheet 2 is thereby so deflected that its subsequent direction of transport y is orthogonal to the original direction of the transport z and the direction of extension x. By means of a second deflection roller 7, and another turning bar 8, the film sheet 2 is again deflected and turned in such a manner that its current direction of transport z′ is in the direction opposite to the original direction of transport z. However, the film sheet 2 is now guided under the film sheet 3. In order to guide the film sheet 2 again in the original direction of transport z, a reversing roller 9 can be used. This exemplary embodiment is shown in FIG. 2. In the exemplary embodiment shown in FIG. 1, the film sheets 2, 3 are deflected around the reversing rollers 9, 10 in such a manner that they can be fed to the winding devices, not shown here, and can be spooled there.

As one can see on the basis of the shades, especially of the film sheet 2 in FIG. 1, the film sheets 2 and 3 are not turned around, but have been interchanged only the direction List of Refernce Symbols 1 Turning station 2 Film sheet 3 Film sheet 4 Guide roller 5 Turning bar 6 Deflection roller 7 Deflection roller 8 Turning bar 9 Reversing roller 10 Reversing roller z, z′ Direction of transport y Direction of extension x Direction of transport 

1. Turning station (1) for changing the mutual orientation of the function layers of film sheets (2,3), which (2,3) are transported along their longitudinal direction (z) and which (2,3) extend along their direction of transport (z) and in a direction (x) orthogonal to it, whereby the function layers of the film sheets (2, 3) follow in sequence in the third spatial direction (y) characterized by the devices (5, 6, 7, 8) for guiding the first film sheet (2), which (5, 6, 7, 8) guide the first film sheet (2) to the other side of the plane, which is formed by the directions of extension (x) and (z) of a second film sheet (3).
 2. Turning station (1) according to claim 1, characterized by the deflecting elements, such as turning bars (4) or deflection rollers (5, 6, 7, 8, 9), are arranged at an inclination with respect to the direction of transport (z) of the film sheets (2, 3).
 3. Turning station (1) according to claim 1, characterized in that the turning bars (4) or the deflection rollers (5, 6, 7, 8, 9), which are arranged at an inclination with respect to the direction of transport (2) of the film sheets (2, 3), are arranged parallel to the plane, which is formed by the directions of extension (x) and (z) of a second film sheet (3).
 4. Turning station (1) according to claim 1, characterized in that the deflecting elements (4, 5, 6, 8, 8, 9), which are arranged at an inclination with respect to the direction of the transport of the film sheets, are turning bars.
 5. Turning station (1) according to claim 1, characterized by at least two turning bars (8) and at least two deflecting rollers.
 6. Turning station (1) according to claim 1, characterized in that, also on the other side of the plane, which is formed by the directions of extension (x) and (z) of the second film (3), devices for deflection (5, 6, 7, 8) of the first film sheet are provided.
 7. Turning station (1) according to claim 1, characterized in that the means for deflection (5, 6, 7, 8) of a first film sheet (2), which comprises, on the other side of the plane formed by the directions of extension (x) and (z) of a second film (3), a turning bar (8), which is inclined with respect to the direction of the transport (y) of the first film sheet (2).
 8. Method for providing at least two film rolls from a film tube extruded from a die head extruder, whereby the film tube is at first cut into film sheets (2, 3) and the latter are thereafter winded on winding shafts and whereby the sequence of the function layers of at least two film sheets (2, 3) is varied in each case on a film roll, characterized in that the variation of the sequence of the function layers of at least two film sheets (2, 3) takes place in each case on a film roll, in that at least two film sheets (2, 3) are fed into at least one turning station (1), which changes the position of the function layers of at least two film sheets (2, 3) in such a manner that the function layers, which were on the inner side of the film tube, lie on the outside and vice versa.
 9. Method according to claim 1, characterized in that the change in the mutual orientation of the function layers of the, at least two, film sheets (2, 3) takes place before the winding with the turning station (1) according to one of the preceding claims 1 to
 7. 10. Method according to claim 1, characterized in that in which the, at least two, film sheets (2, 3) are obtained by cutting a film tube generated by an extruder and which are each later winded at a winding position. 